Implantable cardiac pulse generators (e.g., pacemakers, implantable cardioverter defibrillators (ICD), or etc.) often include elongated medical electrical leads that can be advanced into patient hearts. The electrical leads include electrodes to sense electrical activity and deliver therapeutic stimulation. In recent years, left ventricular (LV) leads are advanced into the coronary sinus in order to position the electrodes of the leads at left ventricular pacing sites, typically located in proximity to the base of the left ventricle.
Some patients may have very small subclavian veins and may require leads smaller than 6 F or 5 F to transverse the small subclavian veins. Some patients may have complex venous anatomies that are difficult to navigate. In order to help navigate in the complex venous anatomies, a guide wire has been commonly used. Although an implanter may be able to get the guide wire to the target site, a quadrapolar LV lead generally has a large diameter which makes it difficult for the LV lead to track a guide wire around acute bends.
Although a variety of LV leads, along with methods for implanting such leads, have been developed, there is still a need in the art for developing downsized LV leads and methods of implantation that facilitate pacing or sensing lateral and posterial basal locations of a heart.